Lung Cancer

Frequently Asked Questions

6. What is the main cause of lung cancer?

Cigarette smoking is the number one cause of lung cancer. Scientists have reported widely on the link between cancer and smoking since the 1960s. Since then, study after study has provided more proof that cigarette smoking is the primary cause of lung cancer.

Before cigarette smoking became popular after World War I, doctors rarely, if ever, saw patients with lung cancer. But today, lung cancer is the leading cause of death by cancer. Over 85 percent of people with lung cancer developed it because they smoked cigarettes.

Using tobacco products has been shown to cause many types of cancer. In fact, smoking tobacco, using smokeless tobacco, and being exposed regularly to second-hand tobacco smoke are responsible for a large number of cancer deaths in the U.S. each year.